Hydroformylation reaction is the reaction that an aldehyde is produced by a reaction between olefins and syngas (CO+H2), wherein the number of carbon atoms of the aldehyde is one more than that of the olefin. The main reason why the hydroformylation technique is widely used in the chemical industry and becomes one of the most important techniques is that the product thereof, aldehydes, is a very useful chemical intermediate. Aldehydes can be used to synthesize carboxylic acids and corresponding esters, and aliphatic amines, etc. The most important application of aldehydes is that they can be converted to alcohols by hydrogenation. Alcohols per se can be widely used as organic solvents, plasticizers, surfactants, or the like in fine chemical engineering field. The study on hydroformylation reaction, especially on the industrialization thereof, is becoming wider and deeper, as the demands for aldehydes and alcohols increase in the industry of fine chemicals, such as plastics, coatings, rubbers, and detergents, which are closely associated with daily life.
CN 102617308 A discloses an olefin biphasic hydroformylation method. The complex catalyst used in the method is formed by polyether guandinium mesylate ionic liquids (PGMILs) with room temperature solidifiable characteristics, RhCl3.3H2O or dicarbonylacetylacetonato rhodium, and triphenylphosphine-3,3′,3″-trisulfonic acid sodium (TPPTS). The reaction is carried out in an autoclave made of stainless steel. The selectivity of high-carbon aldehydes is up to 85˜99%. The molar ratio of normal aldehydes to isomeric aldehydes is from 2.0 to 2.4. However, the reaction uses an ionic liquid, which is expensive and complex to be produced. Rh lost into the product phase is from 0.04% to 0.07%. Although the ionic liquid has advantages such as having a high melting point, having no volatility, and the like, the price thereof is relatively high. In particular, for a high-purity ionic liquid, the purification is complex, and the cost for production is high, which limits the application in industry to certain extent.
CN 102649715 A discloses a method for preparing aldehydes by olefin hydroformylation. In the method, C2-C8 olefins, CO and hydrogen gas are used as raw materials, and an Rh-containing liquid solution is used as the catalyst. The raw materials and the Rh-containing liquid solution catalyst are fed into a highly efficient reactor, being in contact with each other and reacting, to produce a liquid effluent containing aldehydes. The highly efficient reactor used therein is selected from rotating packed bed reactors. U.S. Pat. No. 4,148,830 discloses a hydroformylation method using a liquid phase recycle process. In this method, the resultant aldehyde condensation product is used as a solvent for catalyst. Once the aldehyde product is recovered from the product stream, the medium containing the catalyst is recycled back to the hydroformylation reaction zone. However, in this method, there are some problems in separation of the reaction products and in recovery of the catalyst dissolved uniformly in the reaction products.
U.S. Pat. No. 6,229,052 discloses a hydroformylation reaction, wherein Rh/grafted polymer is used as a fixed bed for catalyzing propylene in gas phase. The gas phase catalytic reaction gives results similar to those of the slurry bed, namely not only the conversion and the activity are relatively low, but also a significant decrease of the activity of the catalyst is observed.
U.S. Pat. No. 4,252,678 discloses the production of a colloidal dispersion containing a transition metal, such as Rh, etc. In this process, the catalyst system is consisted of a transition metal component in form of a colloidal dispersion of 1.0 to 20.0 nm and (styrene/butadiene) functionalized copolymer terminated by a hydroxy group, and is used in the hydroformylation reaction of 1-octene. The catalyst prepared by this method cannot be used in fixed bed reactors and trickle bed reactors, and it is difficult to separate the catalyst from the product.
CN 102281948 A reports polymer-supported transition metal catalyst complexes and methods for use, and produces soluble polymer-supported rhodium catalysts that have a narrow molecular weight distribution. However, all the processes for production of the catalyst, the catalytic reaction, and separation of the catalyst are complex. In the production of the catalyst, it is required to synthesize a soluble polymer by controlling functional monomers and styrene, etc., and then introduce a ligand, and at last support the Rh catalyst. It is required to add compressed gas during the catalytic reaction. The catalyst is separated from the reaction mixture by means of nanofiltration, and the reaction result is not ideal, either.
The paper “Study on the Suzuki Coupling Reaction Catalyzed by Palladium Catalyst supported in Microcapsule Film” (Kaixiao L I, CMFD, No. 8) reports that a Pd-based catalyst is produced by using a microcapsule material, in which phosphorus ligands are connected in the polystyrene microcapsule film, as the support, and used in Suzuki coupling reaction. However, the microcapsule material is a copolymer material, rather than a monopolymer material. The dispersion state of the transition metal component in this catalyst is not mentioned.
In the current industrial production of aldehydes from olefin hydroformylation reaction, Rh-based homogenous catalytic technique and cobalt-based homogeneous catalytic technique are mainly used. Although the reaction activity and selectivity of homogeneous catalysts cannot be achieved by those heterogeneous catalysts, many homogeneous catalysts cannot be scaled up, only because it is difficult to separate the catalyst from the product. During the production, the activity of a catalyst decreases slowly, so it is necessary to discharge a part of the catalyst continuously, while complementing an equal amount of catalyst. Since the price of Rh is high, it is necessary to recover Rh from the stream discharged. The process of this treatment is complex, and causes burden in the production.
Recently, the study of the heterogenization of homogeneous catalysts is of wide interest. The heterogenization techniques of homogeneous catalysts are mainly classified into two categories. One is immobilization of homogeneous catalyst, including immobilization by inorganic supports, immobilization by polymer supports, supported liquid phase catalysts, and supported aqueous phase catalysts. The other is a biphasic catalysis, including liquid/liquid biphasic catalysis, fluorine biphasic system, temperature-controlled phase separation catalysis, supercritical fluid biphasic system, ionic liquid biphasic system and supercritical fluid-ionic liquid biphasic system. Many novel concepts come forth from these catalytic systems. However, in these systems, the loss of active metal is great, or the stability of catalysts is poor, or expansive organic ligands or solvents are used, or the production of the catalyst has a heavy and complicated procedure, complex techniques, and the like, so that all of these systems cannot meet the requirements for industrial production. Concerning heterogeneous catalytic systems, there are only a few reports about improving the catalytic property of a heterogeneous catalyst by adding metal auxiliaries thereto. However, since the catalytic activity of these systems is much lower than those of homogeneous catalytic systems, these systems cannot meet the requirements for industrial production, either.